The present invention relates generally to light sources. Conventional incandescent light bulbs have limited light efficiency. Conventional florescent light bulbs include mercury. Pre-packaged light emitting devices have been used in trailer lights commercially available from Overton""s (Greenville, N.C.), for example, but the LED packaging presents density problems. There is a need for a light source that has long life and high efficiency and that does not create environmental concerns.
Briefly, according to one embodiment of the invention, a light source includes a substrate; an array of un-packaged light emitting semiconductor devices (LESDs), each of the LESDs having at least one surface for emitting light and a substrate surface being attached to the substrate; and a plurality of electrical connections, each electrical connection coupled for providing electrical power to a respective LESD. The LESDs are arranged on the substrate with sufficient density and light generating capability to provide a predetermined irradiation from the light source.